Switching apparatus

ABSTRACT

Switching apparatus that includes a bubble generator, a flexible membrane disposed over the bubble generator and selectively expanded by the bubble generator, and a switch circuit controlled by expansion of the flexible membrane.

BACKGROUND OF THE DISCLOSURE

[0001] Optical fibers are replacing conductive wires in telephone anddata communications, since optical fibers provide extremely highbandwidth, are immune to radio frequency noise, and generate virtuallyno electromagnetic interference. As the cost of optical fibersdecreases, use of optical fibers is expanding to applications thatrequire switching to dynamically reconfigure the interconnection ofoptical signal paths. However, it is often difficult to achieveswitching of optical signals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Features and advantages of the disclosure will readily beappreciated by persons skilled in the art from the following detaileddescription when read in conjunction with the drawing wherein:

[0003]FIGS. 1A and 1B schematically depict an embodiment of a switchingapparatus that includes a bubble generator.

[0004]FIGS. 2A and 2B schematically depict an embodiment of a switchcircuit that can be employed in the embodiment of a switching apparatusdepicted in FIGS. 1A and 1B.

[0005]FIGS. 3A and 3B schematically depict an embodiment of a furtherswitching apparatus that includes a bubble generator.

[0006]FIGS. 4A and 4B schematically depict an embodiment of anotherswitching apparatus that includes a bubble generator.

[0007]FIGS. 5A, 5B and 5C schematically depict an embodiment of yetanother switching apparatus that includes a bubble generator.

[0008]FIGS. 6A and 6B schematically depict an embodiment of a furtherswitching apparatus that includes a bubble generator.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0009]FIGS. 1A and 1B schematically illustrate an embodiment of aswitching apparatus that includes a bubble driven actuator 20 formed forexample of a bubble generator 11 and a flexible membrane 13 disposedover the bubble generator 11. A switch circuit 15 is positioned adjacentthe flexible membrane 13, and the bubble generator 11 is controlled toselectively produce a bubble 12 that causes the flexible membrane 13 toexpand and contactively engage the switch circuit 15, as moreparticularly illustrated in FIG. 1B. The engagement of the flexiblemembrane 13 with the switch circuit 15 controls or actuates the switchcircuit. The bubble generator 11 can be embodied for example as athermal bubble generator similar to thermal bubble generators employedin thermal ink jet printers, and can include a fluid chamber 19, aworking fluid 18 in the fluid chamber, and a heater resistor 21 adjacentthe fluid chamber. By way of illustrative examples, the fluid chamber 19can comprise an opening in a fluid barrier layer 25, and the heaterresistor 21 is formed in an integrated circuit structure 23. An exampleof a thermal bubble generator employed in thermal ink jet printing canbe found in commonly assigned U.S. Pat. No. 5,604,519.

[0010] The switch circuit 15 of the embodiment shown in FIGS. 1A and 1Bcan comprise, for example, electrical, mechanical and/or electro-opticalswitching elements that are selectively engaged by expansion of theflexible membrane.

[0011]FIGS. 2A and 2B schematically depict an embodiment of a switchcircuit 15 that includes a first waveguide 15 a and a second waveguide15 b that are configured to provide an optical path for light energywhen they are engaged such that a beam B in one of the waveguides istransmitted to the other waveguide when the waveguides are engaged. Thefirst waveguide 15 a and the second waveguide 15 b can for example befiber optic waveguides or prisms.

[0012]FIGS. 3A and 3B schematically depict an embodiment of a switchingapparatus that includes a bubble driven actuator 20 formed of a bubblegenerator 11 and a flexible membrane 13 disposed over the bubblegenerator 11. The switching apparatus further includes an optical switchcomprised of a first optical waveguide 15 a and a second opticalwaveguide 15 b that have respective input/output (I/O) ends 115 a, 115 blocated on opposite sides of the bubble generator 11 and opticallyaligned to provide a light path P between such I/O ends when themembrane 13 is not expanded, such that a light beam B emitting from theI/O end of one of the waveguides enters the I/O end of the otherwaveguide when the membrane 13 is not expanded. The opposing I/O ends115 a, 115 b are further positioned sufficiently closely to the plane ofthe flexible membrane 13 such that expansion of the membrane 13 willinterrupt the light path between the I/O ends and block opticaltransmission between of the light beam B, as shown in FIG. 5B. In thismanner, switching is accomplished by selectively generating a bubble todeflect the flexible membrane 13. By way of illustrative example, one ormore of the optical waveguides can be a fiber optic waveguide.

[0013]FIGS. 4A and 4B schematically depict an embodiment of a switchingapparatus that includes a bubble driven actuator 20 formed of a bubblegenerator 11 and a flexible membrane 13 disposed over the bubblegenerator 11, a reflective surface 113 on the flexible membrane 13, andan optical switch circuit that includes a first optical waveguide 15 a,a second optical waveguide 15 b, and a third optical waveguide 15 c. Thefirst optical waveguide 15 a and the second optical waveguide 15 b haverespective input/output (I/O) ends 115 a, 115 b that face each other onopposite sides of the bubble generator 11 and are optically aligned toprovide an optical path P between such I/O ends when the membrane 13 isnot expanded, such that a light beam B emitting from the I/O end 115 aof the first optical waveguide 15 a enters the I/O end 115 b of thesecond optical waveguide 15 b when the membrane 13 is not expanded, sothat a light beam B emitting from the I/O end 115 a of the first opticalwaveguide 15 a, for example, illuminates the I/O end 115 b of the secondoptical waveguide 15 b when the membrane 13 is not expanded. Theopposing I/O ends 115 a, 115 b and an I/O end 115 c of the third opticalwaveguide 15 are further positioned such that expansion of the membrane13 interrupts the optical path P between the I/O ends 115 a, 115 b, andcreates an optical path P′ between the I/O end 115 a of the firstoptical waveguide 15 a and the I/O end 115 c of the third opticalwaveguide 15 c. The optical path P′ more particularly includes a segmentbetween the I/O end 115 a and the reflective surface 113, and anothersegment between the reflective surface 113 and the I/O end 115 c of thethird optical waveguide 15 b. Thus, when the membrane 13 is expanded alight beam B exiting the I/O end 115 a, for example, is reflected towardthe I/O end 115 c, as depicted in FIG. 4B. Switching is accomplished byselectively energizing the bubble generator 11 to generate a bubble thatexpands the flexible reflective membrane 13. By way of illustrativeexample, one or more of the optical waveguides can be a fiber opticwaveguide.

[0014] FIGS. 5A-5C schematically depict an embodiment of a switchingapparatus that includes a bubble driven actuator 20 formed of a bubblegenerator 11 and a flexible membrane 13 disposed over the bubblegenerator 11, a reflective optical element 213 disposed on the flexiblemembrane 13, and an optical switch comprised of a first opticalwaveguide 15 a, a second optical waveguide 15 b, and a third opticalwaveguide 15 c. The first and second optical waveguides includesrespective input/output (I/O) ends 115 a, 115 b that are located onopposite sides of the bubble generator 11 and are optically aligned toprovide an optical path P between such I/O ends when the membrane 13 isnot expanded, such that a light beam B emitting from the I/O end 115 aof the first optical waveguide 15 a enters the I/O end 115 b of thesecond optical waveguide 15 b when the membrane 13 is not expanded, sothat a light beam B emitting from the I/O end 115 a of the first opticalwaveguide 15 a, for example, illuminates the I/O end 115 b of the secondoptical waveguide 15 b when the membrane 13 is not expanded. Theopposing I/O ends 115 a, 115 b and an I/O end 115 c of the third opticalwaveguide 15 are further positioned such that expansion of the membrane13 interrupts the optical path P between the I/O ends 115 a, 115 b, andcreates an optical path P′ between the I/O end 115 a of the firstoptical waveguide 15 a and the I/O end 115 c of the third opticalwaveguide 15 c. The optical path P′ more particularly includes a segmentbetween the I/O end 115 a and the reflective optical element 213, andanother segment between the reflective optical element 213 and the I/Oend 115 c of the third optical waveguide 15 b. Thus, when the membrane13 is expanded a light beam B exiting the I/O end 115 a, for example, isreflected toward the I/O end 115 c, as depicted in FIG. 5B. While theincluded angle between the incident beam and the reflected beam is shownas being approximately a right angle, it should be appreciated that anyappropriate angle could be employed depending upon implementation. Thereflective optical element 213 can implemented for example as a wedgehaving a reflective facet 213 a or a plurality of wedges havingreflective facets 213 a, as shown in FIG. 5C. The wedge or wedges can beformed in the top surface of the flexible membrane 13, for example bylaser ablation. Switching is accomplished by selectively generating abubble to expand the flexible membrane 13. By way of illustrativeexample, one or more of the optical waveguides can be a fiber opticwaveguide.

[0015]FIGS. 6A and 6B schematically depict an embodiment of a switchingapparatus that includes a bubble driven actuator 20 formed of a bubblegenerator 11 and a flexible membrane 13 disposed over the bubblegenerator 11, a light switch element 313 disposed on the flexiblemembrane 13, and an optical switch comprised of a first opticalwaveguide 15 a and a second optical waveguide 15 b. The first opticalwaveguide guides a light beam B and is adjacent the light switch element313 and sufficiently close to the light switch element such that thelight switch element contacts the first optical waveguide when theflexible membrane 13 is expanded. The light switch element 313 includesone or more reflective facets 313 a that are configured to reflect thelight beam B that enters the light switch 313 when the light switch 313is in contact with the first optical waveguide 15 a. It should beappreciated by those skilled in the art that the light extractionperformed by the light switch 313 is based on the principle offrustrated internal reflection wherein the close proximity of the lightswitch 313 to the first optical waveguide 15 a frustrates the totalinternal reflection within the first optical waveguide 15 a of the lightbeam B. An I/O end 115 b of the second optical waveguide 15 c ispositioned to receive the reflected beam B′. Switching is accomplishedby selectively generating a bubble to expand the flexible membrane 13.By way of illustrative example, one or more of the optical waveguidescan be a fiber optic waveguide.

[0016] Although the foregoing has been a description and illustration ofspecific embodiments of the invention, various modifications and changesthereto can be made by persons skilled in the art without departing fromthe scope and spirit of the invention as defined by the followingclaims.

What is claimed is:
 1. A switching apparatus comprising: a bubblegenerator; a flexible membrane disposed over the bubble generator; theflexible membrane being selectively expanded by the bubble generator;and a switch circuit controlled by expansion of the flexible membrane.2. The switching apparatus of claim 1 wherein the bubble generatorcomprises a thermal bubble generator.
 3. The switching apparatus ofclaim 1 wherein the bubble generator comprises a fluid chamber and aheater resistor.
 4. The switching apparatus of claim 1 wherein theswitch circuit comprises an electrical switch circuit.
 5. The switchingapparatus of claim 1 wherein the switch circuit comprises an opticalswitch.
 6. The switching apparatus of claim 1 wherein the switch circuitcomprises a first optical waveguide and a second optical waveguide thatare selectively brought into contact by expansion of the flexiblemembrane.
 7. A switching apparatus comprising: a plurality ofwaveguides; a bubble generator; a flexible membrane disposed over thebubble generator; the flexible membrane being selectively expansion bythe bubble generator; and wherein expansion of the flexible membranecontrols an optical interconnection of the plurality of waveguides. 8.The switching apparatus of claim 7 wherein the bubble generatorcomprises a thermal bubble generator.
 9. The switching apparatus ofclaim 7 wherein the bubble generator comprises a fluid chamber and aheater resistor.
 10. The switching apparatus of claim 7 wherein theplurality of optical waveguides includes a first optical waveguidehaving an end that is optically aligned with an end of a second opticalwaveguide, and wherein displacement of the flexible membrane blocksoptical transmission between the first optical waveguide end and thesecond optical waveguide end.
 11. The switching apparatus of claim 7wherein at least one of the optical waveguides comprises a fiber opticwaveguide.
 12. The switching apparatus of claim 6 wherein the flexiblemembrane is reflective.
 13. A switching apparatus comprising: aplurality of waveguides; a bubble generator; a flexible membranedisposed over the bubble generator; a reflective optical elementdisposed on the flexible membrane; the flexible membrane beingselectively expanded by the bubble generator; and wherein expansion ofthe flexible membrane controls an optical interconnection of theplurality of waveguides.
 14. The switching apparatus of claim 13 whereinthe bubble generator comprises a thermal bubble generator.
 15. Theswitching apparatus of claim 13 wherein the bubble generator comprises afluid chamber and a heater resistor.
 16. The switching apparatus ofclaim 13 wherein the reflective optical element comprises a reflectivesurface disposed on the flexible membrane.
 17. The switching apparatusof claim 13 wherein the reflective optical element comprises areflective facet.
 18. The switching apparatus of claim 13 wherein thereflective optical element comprises a plurality of reflective facets.19. The switching apparatus of claim 13 wherein the plurality of opticalwaveguides includes a first optical waveguide having an end that isoptically aligned with an end of a second optical waveguide, and whereindisplacement of the flexible membrane blocks optical transmissionbetween the first optical waveguide end and the second optical waveguideend.
 20. The switching apparatus of claim 13 wherein the plurality ofoptical waveguides includes a first optical waveguide having an end anda second optical waveguide having an end, and wherein displacement ofthe flexible membrane generates an optical path between the firstoptical waveguide end and the second optical waveguide end.
 21. Aswitching apparatus comprising: means for switching; and means forgenerating a bubble to actuate the means for switching.
 22. A switchingapparatus comprising: a plurality of means for guiding light; and meansfor optically interconnecting the plurality of means for guiding light,said means including means for generating a bubble.
 23. A method ofswitching comprising: generating a bubble to expand a membrane; andengaging a switch circuit with the expanded membrane.
 24. The method ofclaim 23 wherein generating a bubble comprises thermally generating abubble.
 25. The method of claim 23 wherein generating a bubble comprisescontrolling a thermal bubble generator.
 26. The method of claim 23wherein engaging a switch circuit comprises engaging an optical switchcircuit.
 27. The method of claim 23 wherein engaging a switch circuitcomprises pushing a first fiber optic waveguide into contact with asecond fiber optic waveguide.
 28. A method of switching comprising:generating a bubble to expand a membrane; and controlling a light beamwith the expanded membrane.
 29. The method of claim 28 whereingenerating a bubble comprises thermally generating a bubble.
 30. Themethod of claim 28 wherein generating a bubble comprises controlling athermal bubble generator.
 31. The method of claim 28 wherein controllinga light beam comprises reflecting a light beam.
 32. The method of claim28 wherein controlling a light beam comprises interrupting a light beam.